In a multiple antenna wireless LAN environment, wireless APs shares the same wireless resources one another in order to maximize efficiency of the wireless resources. In this case, overall network performance may be deteriorated due to influence caused by inter-user interference and inter-AP interference.
One of the methods to remove the signal interference is done by transmitting frames without the occurrence of interference in transmission and reception of the frames. In this connection, Korean Laid-Open Patent Publication No. 2012-0127833 (laid-open published on Nov. 26, 2012) discloses an arrangement for acquiring interference channel information between a station (STA) and its adjacent STA which is a frame transmission target of a wireless LAN AP, deciding a transmission beam vector based on the interference channel information, and transmitting data frames to the transmission target STA in a MINO transmission manner based on the transmission beam vector.
However, in providing the method of removing the interference, prior arts fail to take into consideration of channel estimation error or describe an interference removal method robust to the channel estimation error in a situation where multiple wireless LAN APs and wireless terminals are equipped with multiple antennas.